Chad's President Idriss Deby has announced he will run for a fifth term in April's elections.
Mr Deby took power in a coup in 1990 and later introduced elections.
A referendum in 2005 scrapped a clause restricting presidents to two terms, but Mr Deby said that if he gets re-elected he will reinstate it.
In the last year, Burundi, Rwanda and Congo-Brazzaville have all changed their constitutions to allow their presidents to run for office again.
Mr Deby said on Tuesday that reinstating term limits would provide "vitality" to the democracy.
"We must limit terms, we must not concentrate on a system in which a change in power becomes difficult," he told the ruling party.
"In 2005 the constitutional reform was conducted in a context where the life of the nation was in danger," he added.
Africa's longest-serving leaders:
- 36 years: Teodoro Obiang Nguema Mbasogo - Equatorial Guinea, took power in a coup in August 1979
- 36 years: Jose Eduardo dos Santos - Angola, took over after death of the country's first president in September 1979
- 35 years: Robert Mugabe - Zimbabwe, won the country's independence elections in April 1980
- 32 years: Paul Biya - Cameroon, took over after resignation of the country's first president in November 1982
- 31 years: Denis Sassou Nguesso - Congo, installed by the military in October 1979, out of power from August 1992-October 1997
- 30 years: Yoweri Museveni - Uganda, became president after his rebel group took power in January 1986